Rapid DNA crossmatch analysis of HLA class II genotypic polymorphisms by temperature gradient gel electrophoresis in unrelated bone marrow donor selection.

The present paper demonstrates the usefulness of the temperature gradient gel electrophoresis (TGGE) as a precise method for the rapid identification of HLA-DR full matched donors by molecular crossmatch analysis. The resulting TGGE fingerprints are highly diverse for different HLA-DR genotypes and identical for samples with identical HLA-DR type, as shown for a panel of 25 randomly selected PCR-SSO pretyped DNA samples. In addition, TGGE analysis of a panel of homozygous typing cell lines (HTCs) established, that even subtle differences in the DR4 subtypes are detectable by TGGE crossmatch analysis. Furthermore, TGGE crossmatch analysis of unrelated donor/patient pairs demonstrated, that only HLA-DR identical patient/donor combinations showed identical TGGE patterns. Thus crossmatch analysis by TGGE presents a novel basis for a rapid and safe unrelated bone marrow donor selection strategy. Only HLA class I identical donors which also show HLA-DR identity in the TGGE crossmatch test are selected for the final confirmation of the HLA class II genes by a suitable DNA subtyping method.